The present invention relates to an apparatus for classifying textile tubes according to the amount of yarn thereon as well as according to the absence of yarn thereon.
In the normal situation, the tubes are unwound until completely empty at the winding stations of a winding machine; that is, they leave the winding station as empty tubes. However, it can happen that a variably large winding remnant may remain, in which the yarn end can no longer be brought to the applicable yarn guide devices or to a yarn splicer within the winding station. As a rule, empty tubes ejected from the winding station, tubes with a small remnant and tubes with a larger, reusable winding remnant are all removed together. Since these bobbins have to be handled differently, detectors that can recognize these different winding states and can control their routing to various transport paths must be used along the common return path.
German Published Patent Application DE-AS 12 78 308 shows an apparatus in which, first, bobbins with a relatively large winding remnant, and then bobbins with a winding remnant that can no longer be reused, are separated from the common return belt. Empty tubes are returned directly to the spinning machine.
While the winding thickness that is still present is detected at the first fork along the path via the deflection of a mechanical scanner, a photooptical detector that is capable of detecting small remaining winding amounts is disposed at the second fork.
German Patent Disclosure Document DE 36 03 002 A1 describes a transport system between a spinning and a winding machine, in which the tubes are mounted on independent carriers. The empty tubes arriving from a common return belt, tubes with a small winding remnant, and tubes with a larger winding remnant are likewise differentiated at a bobbin stripper station. A photoelectric sensor, comprising a light source and a photo sensor, is disposed so as to be located outside the cross section of the tube. Hence the photoelectric sensor is interrupted only if a relatively large winding diameter is present. If so, then this tube is carried onward and returned to the winding machine. If the photoelectric sensor is not interrupted, the tube stripper apparatus becomes operative and pulls the empty tube or the tube with a small winding remnant off the mandrel of the individual carrier vertically. A brush-like feeler is in contact with the outer circumferential face of the empty bobbin and can be rotated by means of a shaft. If the bobbin is pulled off upward and if some remaining yarn is present, this remaining yarn enters into engagement with the feeler, causing the feeler to rotate. This rotation of the feeler is detected by a sensor, which triggers a shunt associated with the stripper device and thereby sorts out empty tubes from tubes having a small yarn remnant.
Known systems thus have separate devices for distinguishing between larger and smaller winding remnants, as well as between empty bobbins and bobbins with a small winding remnant. However, the need still exists for an apparatus which can reliably classify bobbins or yarn packages in a wide variety of classifications according to the amount of yarn, if any, thereon.